Correspondence — Mr. R. B. Neivton — Mr. T. M. Reade. 91 



Edwards Collection of British OHgocene and Eocene Mollusca," to 

 which I beg to offer the following remarks. 



Mr. Jukes-Browne calls attention to the proposed disuse oiCyiherea 

 and Triton ; two generic names which the reviewer discussed when 

 noticing ray book in "Nature" of October 29th, 1891. In a sub- 

 sequent issue of the same Journal (November 12th, 1891), Baron 

 Osten Sacken advocated the retention of Cytherea because the earlier 

 Dipteroid genus of the same name being a synonym, and therefore 

 rendered obsolete, could, from his point of view, be retained for 

 another group. 



Evidently these writers have not consulted the literature dealing 

 with the Molluscan genera under discussion, or the}'^ would have 

 ascertained that Lamarck's Cytherea had been replaced by his earlier 

 Meretrix by many competent authorities such as Dr. J. E. Gray in 

 1847 (Proc. Zool. Soc. p. 183), Deshayes in 1853 (Cat. Conchifera 

 British Museum, p. 34), H. and A. Adams in 1857 (Genera, p. 423), 

 and other specialists, including Dr. Paul Fischer, who, in the latest 

 and most elaborate treatise (Manuel, 1887, p. 1079) on the Mollusca, 

 fully adopts it. 



Concerning the name of Triton, we find that it has been used for 

 three separate organisms: by Linnteus for a Cirripede in 1767; for 

 an Amphibian by Laurent! in 1768 ; and for a Mollusk by De 

 Montfort in 1810. 



Writers on the Eeptilia have ceased to regard it as one of their 

 genera, because the Linn^an name has priority, and they have sub- 

 stituted Molge for it, a genus founded by Merrem in 1820. On 

 the same grounds Malacologists also refuse to acknowledge it (as 

 exemplified by the works of H. and A. Adams, Philippi, Weinkanff, 

 Stoliczka, Zittel, Dall, etc.). Link's Tritonium of 1807 being the name 

 now generally known for this shell, but as this differs from Midler's 

 Tritonium of 1776, 1 have utilized the next most appropriate synonym, 

 and brought into prominence Schumacher's Lampusia of 1817. 



I hope this explanation will serve to show Mr. Jukes-Browne and 

 others interested in this subject that the rejection of Cytherea and 

 Triton as generic names in Zoology, being brought about through 

 the operation of the law of priority, is now almost universally 

 acknowledged. R. Bullen Newton. 



British Museum (Natural History), Cromwell Road, 

 January \?ith, 1892. 



EEADE'S THEOEY OF MOUNTAIN BUILDING. 



Siu, — I read Mr. Jukes-Browne's criticisms of some points in my 

 " Origin of Mountain Eanges " ' with interest, and until I came to 

 the Postscript, which, like a lady's letter, contains the most important 

 part of the communication, contemplated replying to them. This 

 last paragraph however being destructive of the need of the pre- 

 ceding criticisms puts another complexion on the matter. 



Mr. Jukes-Browne must be aware that I have replied to Mr. 

 Davison's arguments against the " expansion theory of Mountain 



1 Geol. Mag. Jan. 1892, p. 24. 



